1. Field
The disclosed technology relates to a temperature control system and a temperature control method of a battery in an energy storage system.
2. Description of the Related Technology
Interest in renewable energy and cooperative storage systems continues to grow for both economic and environmental reasons. Renewable energy can take on various forms, including solar energy, wind energy, geothermal energy, among others. Various factors, including increasing gasoline prices and changes in the global climate have fueled much research and development in various aspects of renewable energy. One such aspect is energy storage systems.
An energy storage system generally includes a storage unit in the form of a battery. The energy storage system can be part of an interconnected network for delivering electricity from suppliers to consumers called an electrical grid. As part of a grid, the energy storage system will store electrical energy when production exceeds consumption, and will supply the stored energy at a later point in time when consumption exceeds production.
Batteries provided in energy storage systems are implemented in the form of rechargeable secondary batteries. Because batteries utilize electrochemical reactions, whose reaction rates often depend exponentially on temperature, maintaining the temperature at which the battery operates can have a large impact on the generated power. For example, a battery that operates at a low temperature (e.g., −20° C. or less) can generate as little as 16% of the power that would otherwise be generated if the battery was operated at a normal operating temperature. In order to prevent power generation from falling at low operating temperatures, various methods have been proposed to maintain the battery temperature within its normal operating temperature. For example, heat generated through dissipation of energy in a resistive load outside of the battery has been employed as one way of maintaining operating temperature. Heat generation via a resistive load has certain drawbacks, for example, including excessive heat which can lead to fire hazard. Therefore, there is a need for a battery temperature control system that does not rely on external resistive heating.